I went through the Cyn install, super easy, but it has its quirks, and I am finding that the Stock S4 was perfect for me. I have tried Odin, Clockword Mod, boot to restore and try zip from SD card with no luck. I have the phone to a point where it will boot, it shows some small yellow and red writing at the top left corner, Samsung splash screen shows, and then the screen goes black. Thats all I get. I've been searching on this topic all over the web, and nothing seems to work. Any help, links to stock roms, which I have found some on sammobile.com but the downloads take hours.